Potassium Carbonate → tert-Butyl 2-nitro-4-(thiophen-2-yl)phenylcarbamate

Participants

Reaction Conditions

Reaction Steps

A mixture of tert-butyl (4-bromo-2-nitrophenyl)carbamate (6.0 g, 18.92 mmol, 1.0 eq.), thiophen-2-ylboronic acid (3.2 g, 24.6 mmol, 1.3 eq.), potassium carbonate (7.84 g, 56.8 mmol, 3.0 eq.) and tetrakis(triphenylphosphine)palladium(0) (1.53 g, 1.32 mmol, 0.07 eq.), tri-tolylphosphine in DME/H2O (105 mL) was first degassed then heated to 90° C. for 20 h. The reaction was then filtered through Celite. The product was extracted with ethyl acetate. The combined organic layers were washed with water and brine, dried over anhydrous Na2SO4, filtered and concentrated under reduced pressure. The crude product was purified by flash column chromatography (silica gel, 2% EtOAc/hexanes) to obtain pure tert-butyl (2-nitro-4-(thiophen-2-yl)phenyl)carbamate (4.42 g, 73% yield).

Provenance & Evidence